Regression Equation .....again
Just a quick question.
I'm going through some practice questions in the first intuition questions banks.
I can get the correct answer to the following question using the high - low method of calculating value of b....
Pretty straightforward and very good and all.....but the answers say the correct way of finding the same answer is the far more convoluted method of ∑x ∑y ∑xy ∑x 2 (squared)
My question I guess is do we ever need to use the longwinded ∑x ∑y....etc etc method? and in what circumstance is it needed rather than the much easier high low method?
My exam is tomorrow so doing lots of last day revision.